aggregate_numpy.py 文件源码

def _sum(group_idx, a, size, fill_value, dtype=None):
    dtype = minimum_dtype_scalar(fill_value, dtype, a)

    if np.ndim(a) == 0:
        ret = np.bincount(group_idx, minlength=size).astype(dtype)
        if a != 1:
            ret *= a
    else:
        if np.iscomplexobj(a):
            ret = np.empty(size, dtype=dtype)
            ret.real = np.bincount(group_idx, weights=a.real,
                              minlength=size)
            ret.imag = np.bincount(group_idx, weights=a.imag,
                              minlength=size)
        else:
            ret = np.bincount(group_idx, weights=a,
                              minlength=size).astype(dtype)

    if fill_value != 0:
        fill_untouched(group_idx, ret, fill_value)
    return ret